Specifically in the field of application of this invention, it is known to provide time-continued integrated filters, using a transconductor stage as the filter base block. That technique has been developed in recent years and already seems to be the most effective for high-frequency applications. This is most likely attributable to that, in a transconductor filter, the voltage/current conversion step is carried out in an open-loop system, and accordingly, the so-called non-dominant pole of the converter suffers no limitations from the unit frequency gain of an operational amplifier, as is instead the case with filters in the MOSFET-C technology.
However, transconductor filters also have the disadvantage of being uniquely affected by temperature changes while in operation. This results in the transconductance value fluctuating, which may be undesirable for many applications.
The underlying technical problem of this invention is to provide a circuit device which has such structural and functional characteristics as to neutralize the dependence of the differential stage transconductance on temperature, thereby overcoming the limitations imposed on current embodiments.